Shorting post loaded annular microstrip antenna is of considerable interest. Recent works have presented formulations for annular microstrip patch with a shorting post located at the centre of a circular disc, thereby converting the structure to an annular ring with a centre shot. A theoretical formulation for multiple post loading (up to ten posts) of an annular patch is presented. The posts are ...
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The fast multipole method (FMM) is developed to analyse electromagnetic scattering using higher-order hierarchical Legendre basis functions, which have been proposed recently and make the impedance matrix, from method of moments, a low condition number. In this method, the point-to-point based-on-sample quadrature is used because the basis functions are defined on large surface patches of scattere...
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The boundary-value problem of two coaxial lines cross-coupled to a rectangular waveguide is solved. The techniques of Fourier transform, mode matching, image method and superposition are used to obtain an analytic solution. Residue calculus and Poisson's summation formula are employed to transform the solution into a fast convergent series that is numerically efficient. Computations are performed ...
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A binomial low-pass filter provides the flattest pass-band response but slow attenuation transition. A design for improving the roll-off performance based on the negative-epsiv property of complementary split-ring resonators is presented, whilst maintaining the filter pass-band performance. By properly designing and integrating the complementary split-ring resonators with the low-pass filter, not ...
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Frequency-selective surfaces (FSSs) with two sharp sidebands have been investigated, which are constructed by cascading and shunting two substrate integrated waveguide cavities (SIWCs) of different sizes with periodic slots at top and bottom metal surfaces. The lower and upper sharp sidebands are induced by two transmission nulls that are generated by coupling between the slot aperture resonance a...
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Novel types of antenna arrays constructed from combination of linear and elliptical antenna arrays are presented. These types are called elliptical, concentric elliptical, elliptical cylindrical and elliptical coaxial cylindrical arrays where only the array factors are considered. The effect of the element factor can be considered separately and combined to the array factor. The expression for the...
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Rectangular waveguide (RW) with sidewalls of vertical conducting cylinders (i.e. SIW, substrate-integrated waveguide) becomes popular with the advent of low-temperature co-fired ceramic structure; its analysis is usually numerical, or modal, leading to empirical design formulas. However, its analytical equivalence to the common RW of the solidwall is identified; in other words, analytical design f...
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Methods to mitigate the strong dependence of impedance bandwidth on the ground- plane size for a rectangular printed planar monopole is described. It is shown that the bandwidth limitation may be overcome by introducing feed-line asymmetry, which alters the purity and the Q of the higher frequency modes and by ground-plane augmentation, which effects the lower frequency modes. A method of extendin...
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A compact planar E-plane monopulse antenna is proposed and realised at 36.5 GHz for millimetre-wave radar or direction-finding system application, which is built on the substrate integrated waveguide (SIW) technology. A phase shifter having a non-uniform SIW width configuration is self-consistently made of a periodically embedded via array and it can achieve good performances over a relative broad...
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A novel open-ended waveguide cavity resonator for the microwave curing of bumps, underfills and encapsulants is described. The open oven has the potential to provide fast alignment of devices during flip-chip assembly, direct chip attach, surface mount assembly or wafer-scale level packaging. The prototype microwave oven was designed to operate at X-band for ease of testing, although a higher freq...
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An electrically small antenna is extremely inefficient when operating over a large (multi-octave) bandwidth in a conventional radiating system. As a result, a large amount of prime battery power would be needed to generate sufficient radio frequency (RF) signal power to overcome the poor antenna efficiency and to induce the desired amount of radiation. An alternative method is described in which e...
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A simple equivalent circuit of the edge coupled microstrip ring resonator is developed based on both circuit and electromagnetic theory. The new model extends the work done by previous authors by including the effects of radiation loss, the coupling gap and the feed network as well as extending the frequency range by including higher-order modes. The model accurately predicts the resonant frequenc...
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Arrays of N weakly coupled oscillators are considered in different configurations. The locking bandwidth for these arrays is defined statistically. Various factors affecting the locking bandwidth and the effect of the coupling network topology on locking bandwidth are studied by solving the dynamic equations of the array numerically. The analytical locking bandwidth for two configurations of array...
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A compact active integrated microstrip antenna with circular polarisation (CP) diversity for a global positioning system (GPS) receiver is presented. As a radiator, a diamond-shaped micro- strip ring patch with four embedded slots has been newly proposed to realise wide impedance bandwidth, compact size and dual CP. The active circuitry, consisting of both switching circuits and a small signal amp...
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A Ka-band oscillator with a high-Q low-temperature co-fired ceramic circular resonator is presented. The resonator, including zigzagged dual-row via posts for tightly confined electromagnetic power as a metallic boundary wall, is presented. The unloaded-Q of the proposed resonator is improved by 22.1% compared to that of a conventional one with vertical via posts. Another resonator is fed with a l...
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The design of several universal mobile telecommunications system multi-antenna systems with radiators having a high isolation, a high total efficiency and a low envelope correlation is presented. First, two planar inverted-F antennas (PIFAs), closely positioned at the top edge of a small ground plane whose size is representative of the printed circuit board of a mobile phone, are described. A tech...
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The multilayered microwave filters are developed with the assistance of two transmission zeros. Besides a coupled line connected to one capacitor, another capacitor cross coupled between the source and load ports is utilised for the proposed filters. By properly adjusting the coupling coefficients between the coupled line and two capacitors, two transmission zeros would appear on the lower side, t...
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